As high technology is developed gradually, a video product (e.g. digital video or image device) has become a popular product in the daily live. According to the digital video or image device, a liquid crystal displaying panel is an important component so as to display the correlative information. The user can read the necessary information from this liquid crystal displaying panel.
Referring to FIGS. 1 and 2, a conventional liquid crystal displaying panel 10 includes a thin film transistor (TFT) array substrate 20, a color filter (CF) substrate 40 and a liquid crystal 12. The liquid crystal 12 is located between the TFT array substrate 20 and the CF substrate 40. The TFT array substrate 20 includes a plurality of gate electrodes 22, a gate insulating layer 24, a plurality of channel components 25, a plurality of drain electrodes 26, a plurality of source electrodes 28, a passivating layer 30 and a plurality of pixel electrodes 32, which all are formed on a glass substrate 34 in sequence, wherein each gate electrode 22, gate insulating layer 24, channel component 25, drain electrode 26 and source electrode 28 can be formed to a thin film transistor (TFT) 21. The channel component 25 includes first and second semiconductor layers 25a, 25b, wherein the first semiconductor layer 25a is an active layer, and the second semiconductor layer 25b is an ohmic contact layer containing N-type dopant. A plurality of gate lines 52 are disposed on the glass substrate 34. The gate insulating layer 24 covers the gate lines 52. A plurality of data lines 54 are disposed on the gate insulating layer 24. Two adjacent gate lines 52 and two adjacent data lines 54 define a pixel 56. The common electrode 33a is located at one side of the pixel 56. The passivating layer 30 covers the data lines 54. A plurality of pixel electrodes 32 are disposed on the passivating layer 30, and located in the pixels 56 respectively. The CF substrate 40 includes a plurality of black matrices 48, a color filter layer 42 and a transparent electrode 44, which all are formed on another glass substrate 46 in sequence.
Recently, a conductive line which is used in the liquid crystal displaying panel is mainly made of aluminum metal (Al metal) or aluminum alloy (Al alloy), because Al metal or Al alloy has low resistance value and is easily made. However, as the liquid crystal displaying panel with big size is popular gradually, the conductive line having much low resistance value must be developed quickly, i.e. maybe the conductive line will be mostly made of copper metal (Cu metal) replacing Al metal or Al alloy.
When the copper conductive line is developed, there is a problem that the adhesion between the copper conductive line and the glass substrate is not good. In order to solve this problem, an adhesive layer is added to be disposed between the copper conductive line and the glass substrate, thereby helpfully increasing the adhesion between the copper conductive line and the glass substrate. However, generally the resistance value of the adhesive layer is not low so as to increase the resistance value of the copper conductive line. Or, the adhesive layer and the copper conductive line do not have similar etching property when the adhesive layer and the copper conductive line are etched. Thus, the manufacture cost can be increased.
In addition, when the copper conductive line is developed, there is another problem that the copper (Cu) of the copper conductive line and the silicon (Si) of the semiconductor layer containing N-type dopant can be diffused to each other.
Accordingly, there exists a need for a method for manufacturing a TFT array substrate capable of solving the above-mentioned problems.